ENS -
The first time I went up Rainier I did some hiking and a Crevasse Rescue class with RMI. The next day I went up to just below Muir with a bud (spent the night there), then up to Ingram Flats for a little sleep, and then an early start for the summit. This provides time to acclimate. If we would have planned better, we would have had a permit to spend the night back at Muir or the Flats on the way down too. That last day was pretty long.
Be careful on the snowfield btw Paradise and Muir. Make sure you're good w/ map & compass or are prepared to sit out whiteout conditions (unless there's a good boot track).
The Evil Dark Lord has the best book on Rainier ...